lockfree/detail/uses_optional.hpp

0001 //  Copyright (C) 2023 Tim Blechmann
0002 //
0003 //  Distributed under the Boost Software License, Version 1.0. (See
0004 //  accompanying file LICENSE_1_0.txt or copy at
0005 //  http://www.boost.org/LICENSE_1_0.txt)
0006
0007 #ifndef BOOST_LOCKFREE_DETAIL_USES_OPTIONAL_HPP
0008 #define BOOST_LOCKFREE_DETAIL_USES_OPTIONAL_HPP
0009
0010 #include <boost/config.hpp>
0011
0012 #ifndef BOOST_NO_CXX17_HDR_OPTIONAL
0013
0014 #    include <optional>
0015
0016 namespace boost { namespace lockfree {
0017
0018 struct uses_optional_t
0019 {};
0020
0021 #    ifdef BOOST_NO_CXX17_INLINE_VARIABLES
0022 static
0023 #    else
0024 inline
0025 #    endif
0026     constexpr uses_optional_t uses_optional;
0027
0028 }} // namespace boost::lockfree
0029
0030 #endif
0031
0032 #endif /* BOOST_LOCKFREE_DETAIL_USES_OPTIONAL_HPP */